Controlled degradable chitosan/collagen composite scaffolds for application in nerve tissue regeneration

The biodegradable materials have been widely used for fabricating various scaffolds in the application of peripheral nerve tissue engineering. The porous chitosan/collagen composite scaffolds with different tailored degradation ratio may be a candidate. In the present study, the porous chitosan/collagen composite scaffolds were prepared by controlled lyophylization and phase separation of corresponding composite solutions with different proportion of chitosan and collagen. The scaffolds were investigated via morphology, porosity, liquid uptake, swelling behavior, component, mechanical and In Vitro degradation testing. The cytotoxicity and cytocompatibility of the prepared composite scaffolds were evaluated using L929 fibroblasts, RSC96 cell lines and primary Schwann cells, respectively. The related molecular mechanism was further penetrated by RT-PCR and Western Blot. Finally, the In Vivo degradation behavior and inflammatory reaction were examined by subcutaneous implantation of rabbit. The results showed that the chitosan/collagen composite scaffolds possessed a surface fiber-like structure while inner porosity. Compared to a pure collagen scaffold, the addition of chitosan decreased the mean pore size, liquid uptake and degradation rate, while increased the mechanical property of the composite scaffolds. Physicochemical properties of scaffolds including porosity, swelling behavior and component were found satisfactory for intended application. The chitosan/collagen composite scaffolds showed good cytocompatibility without cytotoxicity. And our results also demonstrated that the chitosan/collagen composite scaffolds could promote the attachment, migration and proliferation of Schwann cells. The In Vivo implantation results indicated that the composites scaffolds showed obviously modulated degradation behavior without causing any inflammatory reaction. Taken together, the developed chitosan/collagen composite scaffolds here may have good potential promising application as scaffolds materials for peripheral nerve regeneration.